1. Field of the Invention
The present invention generally relates to a communication method, a communication system and a communication device. More specifically, the present invention relates to a communication method for performing a bidirectional serial communication, a communication system and a communication device.
2. Description of the Related Art
There is an example of a communication system for performing bidirectional serial communications. Patent Document 1 discloses that data and clocks are subjected to time-division so as to be multiplexed and transmitted by one bus line, another bus line for determining receipt and sending is used, and data are mutually sent and received by these two bus lines.
Patent Document 1 discloses that, at the sending time, a latch circuit outputs a power supply voltage Vcc of an IN terminal at data H received from a data input unit to a contact point a of a switch in synchronization with a clock signal from a clock circuit, the contact point a is divided with resistors R1 and R2 by data L to obtain divided voltage values, the switch is changed over by the clock signal to a or b, the data are output at a, and the clock signal is output at b. It further discloses that, at the receiving time, a signal input into a separation circuit from a sending and receiving changeover switch is separated by a level determination to data and a clock signal, the data are latched and wave-shaped by a latch and shaping circuit and then output. It further discloses that, at the sending time, a decoder operates a level of the send and receive determining line and a receive request input H, outputs H, changes over the sending and receiving changeover switch to a sending side to set the send and receive determining line to be L, and the data and the clock signal are subjected to time-division and transmitted by a bus line.
Patent Document 2 discloses that an information block is divided into plural sub blocks including plural segments, plural inverted sub blocks obtained by inverting all information allocated to each of the plural segments included in the original sub blocks are generated in association with the original sub blocks, and the plural original blocks and the generated inverted sub blocks are integrated in order to convert information blocks to code blocks.
The example of the communication system has a problem that a data and clock transmission line and a send and receive determining line are necessary for the Serial communication and the serial communication cannot be achieved using only one signal line.
[Patent Document 1] Japanese Laid-open Patent Publication No. H07-95248
[Patent Document 2] Japanese Laid-open Patent Publication No. 2000-124960